net: mscc: Add SPDX identifier

ocelot_qsys.h is missing the SPDX identfier, fix that.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: NAllan W. Nielsen <allan.nielsen@microsemi.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot_qsys.h

+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
 /*
  * Microsemi Ocelot Switch driver
  *
- * License: Dual MIT/GPL
  * Copyright (c) 2017 Microsemi Corporation
  */